WPA: Extend the wpa_pmk_to_ptk() function to also derive KDK

Extend the wpa_pmk_to_ptk() to also derive Key Derivation
Key (KDK), which can later be used for secure LTF measurements.

Update the wpa_supplicant and hostapd configuration and the
corresponding WPA and WPA Auth state machine, to allow enabling of KDK
derivation. For now, use a testing parameter to control whether KDK is
derived.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>

diff --git a/hostapd/config_file.c b/hostapd/config_file.c
index b3dc8f81a99984b8e7e4a3327c8ae2694e105877..05dc96736e1f553aa8a07ddb29d005cb2e68e5f1 100644 (file)
--- a/hostapd/config_file.c
+++ b/hostapd/config_file.c
@@ -4577,6 +4577,12 @@ static int hostapd_config_fill(struct hostapd_config *conf,
                bss->disable_11ac = !!atoi(pos);
        } else if (os_strcmp(buf, "disable_11ax") == 0) {
                bss->disable_11ax = !!atoi(pos);
+#ifdef CONFIG_PASN
+#ifdef CONFIG_TESTING_OPTIONS
+       } else if (os_strcmp(buf, "force_kdk_derivation") == 0) {
+               bss->force_kdk_derivation = atoi(pos);
+#endif /* CONFIG_TESTING_OPTIONS */
+#endif /* CONFIG_PASN */
        } else {
                wpa_printf(MSG_ERROR,
                           "Line %d: unknown configuration item '%s'",

diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index f7a344e0ea4daa082870c5d4cdd7ccf0d959bde5..4eb4ee2729d64730fac3c88b338c5c720c7b02a2 100644 (file)
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -862,6 +862,16 @@ struct hostapd_bss_config {
         */
        u8 mka_psk_set;
 #endif /* CONFIG_MACSEC */
+
+#ifdef CONFIG_PASN
+#ifdef CONFIG_TESTING_OPTIONS
+       /*
+        * Normally, KDK should be derived if and only if both sides support
+        * secure LTF. Allow forcing KDK derivation for testing purposes.
+        */
+       int force_kdk_derivation;
+#endif /* CONFIG_TESTING_OPTIONS */
+#endif /* CONFIG_PASN */
 };
 
 /**

diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
index 82a97468d62dbf7631d6cc5a0231c4c1d7dae43f..ebf35cf30fe586f96c043c7d657690ed932e224d 100644 (file)
--- a/src/ap/wpa_auth.c
+++ b/src/ap/wpa_auth.c
@@ -2290,7 +2290,8 @@ static int wpa_derive_ptk(struct wpa_state_machine *sm, const u8 *snonce,
                akmp |= WPA_KEY_MGMT_PSK_SHA256;
        return wpa_pmk_to_ptk(pmk, pmk_len, "Pairwise key expansion",
                              sm->wpa_auth->addr, sm->addr, sm->ANonce, snonce,
-                             ptk, akmp, sm->pairwise, z, z_len);
+                             ptk, akmp, sm->pairwise, z, z_len,
+                             sm->wpa_auth->conf.kdk ? WPA_KDK_MAX_LEN : 0);
 }
 
 

diff --git a/src/ap/wpa_auth.h b/src/ap/wpa_auth.h
index 5f9df9c89bebe98c4446b72452cba703d9abe2c3..5dc3cc5c6d30aa9348fcdfb34383187b10dfb94c 100644 (file)
--- a/src/ap/wpa_auth.h
+++ b/src/ap/wpa_auth.h
@@ -262,6 +262,12 @@ struct wpa_auth_config {
 #ifdef CONFIG_DPP2
        int dpp_pfs;
 #endif /* CONFIG_DPP2 */
+
+       /*
+        * If set Key Derivation Key should be derived as part of PMK to
+        * PTK derivation.
+        */
+       bool kdk;
 };
 
 typedef enum {

diff --git a/src/ap/wpa_auth_glue.c b/src/ap/wpa_auth_glue.c
index c01654f38c8ba561b6eb966f6bd2dc0dfcff87ad..a829361b5853e6f5971fe5815b72b237f28351e7 100644 (file)
--- a/src/ap/wpa_auth_glue.c
+++ b/src/ap/wpa_auth_glue.c
@@ -208,6 +208,11 @@ static void hostapd_wpa_auth_conf(struct hostapd_bss_config *conf,
 #ifdef CONFIG_DPP2
        wconf->dpp_pfs = conf->dpp_pfs;
 #endif /* CONFIG_DPP2 */
+#ifdef CONFIG_PASN
+#ifdef CONFIG_TESTING_OPTIONS
+       wconf->kdk = conf->force_kdk_derivation;
+#endif /* CONFIG_TESTING_OPTIONS */
+#endif /* CONFIG_PASN */
 }
 
 

diff --git a/src/common/wpa_common.c b/src/common/wpa_common.c
index 3d04650d329917c2ab64f9513a13ed7ea3b154d3..750a3c8c43fac19e099add9acfa61415a812166f 100644 (file)
--- a/src/common/wpa_common.c
+++ b/src/common/wpa_common.c
@@ -333,6 +333,7 @@ int wpa_eapol_key_mic(const u8 *key, size_t key_len, int akmp, int ver,
  * @ptk: Buffer for pairwise transient key
  * @akmp: Negotiated AKM
  * @cipher: Negotiated pairwise cipher
+ * @kdk_len: The length in octets that should be derived for KDK
  * Returns: 0 on success, -1 on failure
  *
  * IEEE Std 802.11i-2004 - 8.5.1.2 Pairwise key hierarchy
@@ -348,12 +349,13 @@ int wpa_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const char *label,
                   const u8 *addr1, const u8 *addr2,
                   const u8 *nonce1, const u8 *nonce2,
                   struct wpa_ptk *ptk, int akmp, int cipher,
-                  const u8 *z, size_t z_len)
+                  const u8 *z, size_t z_len, size_t kdk_len)
 {
 #define MAX_Z_LEN 66 /* with NIST P-521 */
        u8 data[2 * ETH_ALEN + 2 * WPA_NONCE_LEN + MAX_Z_LEN];
        size_t data_len = 2 * ETH_ALEN + 2 * WPA_NONCE_LEN;
-       u8 tmp[WPA_KCK_MAX_LEN + WPA_KEK_MAX_LEN + WPA_TK_MAX_LEN];
+       u8 tmp[WPA_KCK_MAX_LEN + WPA_KEK_MAX_LEN + WPA_TK_MAX_LEN +
+               WPA_KDK_MAX_LEN];
        size_t ptk_len;
 #ifdef CONFIG_OWE
        int owe_ptk_workaround = 0;
@@ -395,16 +397,24 @@ int wpa_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const char *label,
                data_len += z_len;
        }
 
+       if (kdk_len > WPA_KDK_MAX_LEN) {
+               wpa_printf(MSG_ERROR,
+                          "WPA: KDK len=%zu exceeds max supported len",
+                          kdk_len);
+               return -1;
+       }
+
        ptk->kck_len = wpa_kck_len(akmp, pmk_len);
        ptk->kek_len = wpa_kek_len(akmp, pmk_len);
        ptk->tk_len = wpa_cipher_key_len(cipher);
+       ptk->kdk_len = kdk_len;
        if (ptk->tk_len == 0) {
                wpa_printf(MSG_ERROR,
                           "WPA: Unsupported cipher (0x%x) used in PTK derivation",
                           cipher);
                return -1;
        }
-       ptk_len = ptk->kck_len + ptk->kek_len + ptk->tk_len;
+       ptk_len = ptk->kck_len + ptk->kek_len + ptk->tk_len + ptk->kdk_len;
 
        if (wpa_key_mgmt_sha384(akmp)) {
 #if defined(CONFIG_SUITEB192) || defined(CONFIG_FILS)
@@ -488,6 +498,12 @@ int wpa_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const char *label,
        os_memcpy(ptk->tk, tmp + ptk->kck_len + ptk->kek_len, ptk->tk_len);
        wpa_hexdump_key(MSG_DEBUG, "WPA: TK", ptk->tk, ptk->tk_len);
 
+       if (kdk_len) {
+               os_memcpy(ptk->kdk, tmp + ptk->kck_len + ptk->kek_len +
+                         ptk->tk_len, ptk->kdk_len);
+               wpa_hexdump_key(MSG_DEBUG, "WPA: KDK", ptk->kdk, ptk->kdk_len);
+       }
+
        ptk->kek2_len = 0;
        ptk->kck2_len = 0;
 

diff --git a/src/common/wpa_common.h b/src/common/wpa_common.h
index 23e5418e6c5fa11acbffd3f7b21118b1ed3f9567..44b803e65370603159978ca97d00f9c04608e492 100644 (file)
--- a/src/common/wpa_common.h
+++ b/src/common/wpa_common.h
@@ -216,6 +216,7 @@ struct wpa_eapol_key {
 #define WPA_KCK_MAX_LEN 32
 #define WPA_KEK_MAX_LEN 64
 #define WPA_TK_MAX_LEN 32
+#define WPA_KDK_MAX_LEN 32
 #define FILS_ICK_MAX_LEN 48
 #define FILS_FT_MAX_LEN 48
 
@@ -229,11 +230,13 @@ struct wpa_ptk {
        u8 tk[WPA_TK_MAX_LEN]; /* Temporal Key (TK) */
        u8 kck2[WPA_KCK_MAX_LEN]; /* FT reasoc Key Confirmation Key (KCK2) */
        u8 kek2[WPA_KEK_MAX_LEN]; /* FT reassoc Key Encryption Key (KEK2) */
+       u8 kdk[WPA_KDK_MAX_LEN]; /* Key Derivation Key */
        size_t kck_len;
        size_t kek_len;
        size_t tk_len;
        size_t kck2_len;
        size_t kek2_len;
+       size_t kdk_len;
        int installed; /* 1 if key has already been installed to driver */
 };
 
@@ -383,7 +386,7 @@ int wpa_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const char *label,
                   const u8 *addr1, const u8 *addr2,
                   const u8 *nonce1, const u8 *nonce2,
                   struct wpa_ptk *ptk, int akmp, int cipher,
-                  const u8 *z, size_t z_len);
+                  const u8 *z, size_t z_len, size_t kdk_len);
 int fils_rmsk_to_pmk(int akmp, const u8 *rmsk, size_t rmsk_len,
                     const u8 *snonce, const u8 *anonce, const u8 *dh_ss,
                     size_t dh_ss_len, u8 *pmk, size_t *pmk_len);

diff --git a/src/rsn_supp/wpa.c b/src/rsn_supp/wpa.c
index 834658324ee4608b87b81f87fcae329a91b62ec5..24d7422bf5b2b8a01e13093fd55eade62fa2475f 100644 (file)
--- a/src/rsn_supp/wpa.c
+++ b/src/rsn_supp/wpa.c
@@ -606,7 +606,8 @@ static int wpa_derive_ptk(struct wpa_sm *sm, const unsigned char *src_addr,
        return wpa_pmk_to_ptk(sm->pmk, sm->pmk_len, "Pairwise key expansion",
                              sm->own_addr, sm->bssid, sm->snonce,
                              key->key_nonce, ptk, akmp,
-                             sm->pairwise_cipher, z, z_len);
+                             sm->pairwise_cipher, z, z_len,
+                             sm->kdk ? WPA_KDK_MAX_LEN : 0);
 }
 
 
@@ -3184,6 +3185,7 @@ void wpa_sm_set_config(struct wpa_sm *sm, struct rsn_supp_config *config)
                sm->p2p = config->p2p;
                sm->wpa_rsc_relaxation = config->wpa_rsc_relaxation;
                sm->owe_ptk_workaround = config->owe_ptk_workaround;
+               sm->kdk = config->kdk;
 #ifdef CONFIG_FILS
                if (config->fils_cache_id) {
                        sm->fils_cache_id_set = 1;
@@ -3206,6 +3208,7 @@ void wpa_sm_set_config(struct wpa_sm *sm, struct rsn_supp_config *config)
                sm->wpa_rsc_relaxation = 0;
                sm->owe_ptk_workaround = 0;
                sm->beacon_prot = 0;
+               sm->kdk = false;
        }
 }
 

diff --git a/src/rsn_supp/wpa.h b/src/rsn_supp/wpa.h
index 2142772d730c5f6c4c890d5726bac529ed231d63..fda3979dff96e1fb4138566df1cdd1ae8695303f 100644 (file)
--- a/src/rsn_supp/wpa.h
+++ b/src/rsn_supp/wpa.h
@@ -130,6 +130,7 @@ struct rsn_supp_config {
        int owe_ptk_workaround;
        const u8 *fils_cache_id;
        int beacon_prot;
+       bool kdk;
 };
 
 #ifndef CONFIG_NO_WPA

diff --git a/src/rsn_supp/wpa_i.h b/src/rsn_supp/wpa_i.h
index 96b07fc68baf1145261730d75e9de09ffbe81471..1ac453c7769472d3e1984cfbb6fb9ffabd40c26d 100644 (file)
--- a/src/rsn_supp/wpa_i.h
+++ b/src/rsn_supp/wpa_i.h
@@ -73,6 +73,12 @@ struct wpa_sm {
                             * to be used */
        int keyidx_active; /* Key ID for the active TK */
 
+       /*
+        * If set Key Derivation Key should be derived as part of PMK to
+        * PTK derivation.
+        */
+       bool kdk;
+
        u8 own_addr[ETH_ALEN];
        const char *ifname;
        const char *bridge_ifname;

diff --git a/wlantest/rx_eapol.c b/wlantest/rx_eapol.c
index 1e5d66735510e8056854ba1aab330acd70854538..cdc1fff0c38ecaf14924bfea56fafcbadd80fba5 100644 (file)
--- a/wlantest/rx_eapol.c
+++ b/wlantest/rx_eapol.c
@@ -128,7 +128,7 @@ static int try_pmk(struct wlantest *wt, struct wlantest_bss *bss,
                                  "Pairwise key expansion",
                                  bss->bssid, sta->addr, sta->anonce,
                                  sta->snonce, &ptk, sta->key_mgmt,
-                                 sta->pairwise_cipher, NULL, 0) < 0 ||
+                                 sta->pairwise_cipher, NULL, 0, 0) < 0 ||
                   check_mic(ptk.kck, ptk.kck_len, sta->key_mgmt, ver, data,
                             len) < 0) {
                return -1;

diff --git a/wpa_supplicant/config.c b/wpa_supplicant/config.c
index 4c1e422602a9c3d873f672da066f4e85aaeccc59..60129cf4830ccce3b98006acb9fd348ac7942b44 100644 (file)
--- a/wpa_supplicant/config.c
+++ b/wpa_supplicant/config.c
@@ -5149,6 +5149,11 @@ static const struct global_parse_data global_fields[] = {
        { INT_RANGE(extended_key_id, 0, 1), 0 },
 #endif /* CONFIG_WNM */
        { INT_RANGE(wowlan_disconnect_on_deinit, 0, 1), 0},
+#ifdef CONFIG_PASN
+#ifdef CONFIG_TESTING_OPTIONS
+       { INT_RANGE(force_kdk_derivation, 0, 1), 0 },
+#endif /* CONFIG_TESTING_OPTIONS */
+#endif /* CONFIG_PASN */
 };
 
 #undef FUNC

diff --git a/wpa_supplicant/config.h b/wpa_supplicant/config.h
index 611b9931896f56728ebb6ad7a3d31852d5850c32..6ce737c03a24bb3875ccd12e9db4e51bbbd3207f 100644 (file)
--- a/wpa_supplicant/config.h
+++ b/wpa_supplicant/config.h
@@ -1608,6 +1608,16 @@ struct wpa_config {
         * 1 = Trigger disconnection
         */
        int wowlan_disconnect_on_deinit;
+
+#ifdef CONFIG_PASN
+#ifdef CONFIG_TESTING_OPTIONS
+       /*
+        * Normally, KDK should be derived if and only if both sides support
+        * secure LTF. Allow forcing KDK derivation for testing purposes.
+        */
+       int force_kdk_derivation;
+#endif /* CONFIG_TESTING_OPTIONS */
+#endif /* CONFIG_PASN*/
 };
 
 

diff --git a/wpa_supplicant/wpas_glue.c b/wpa_supplicant/wpas_glue.c
index a9a66baadd80efd19195f74916e3ce94b6182ef1..6cee1e7909d05416408af5ca1557b47f109c8e2a 100644 (file)
--- a/wpa_supplicant/wpas_glue.c
+++ b/wpa_supplicant/wpas_glue.c
@@ -1451,5 +1451,10 @@ void wpa_supplicant_rsn_supp_set_config(struct wpa_supplicant *wpa_s,
 #endif /* CONFIG_FILS */
                conf.beacon_prot = ssid->beacon_prot;
        }
+#ifdef CONFIG_PASN
+#ifdef CONFIG_TESTING_OPTIONS
+       conf.kdk = wpa_s->conf->force_kdk_derivation;
+#endif /* CONFIG_TESTING_OPTIONS */
+#endif /* CONFIG_PASN*/
        wpa_sm_set_config(wpa_s->wpa, ssid ? &conf : NULL);
 }